The government's and the Bank of England's announcement of emergency help for banks in the form of cut price "funding for lending" and extra liquidity has had an instant impact. One money market contact reports that Barclays was on Thursday paying 1.2% for six-month money, whereas today the lender should be able to access funds of the same duration at 0.85%.

In itself, that counts as a chunky movement (as does the jump in UK banks' share prices – Royal Bank of Scotland up 8.7%, Barclays 7.6% and Lloyds 5%). But can movements of that size in the cost of bank funding, when translated into fractionally lower rates for end-borrowers, really stimulate demand for new loans for productive purposes?

One suspects the effect will be minimal. "Welcome, but limited" was the verdict on the schemes from Graham Leach, chief economist at the Institute of Directors. His view? "The liquidity scheme will need to be massively expanded if break-up and contagion spread across the eurozone. The funding for lending scheme helps the supply of money, and the demand for it, by lowering the cost of borrowing. But the core problem remains: companies alarmed by the euro crisis will not be eager to borrow regardless of the cost."

That sounds correct. The biggest challenge here is to persuade companies to invest in productive assets. At the moment, many are too terrified that even tentative projections on returns on capital will blown apart by a disaster in the eurozone.

Yes, it's sensible for the Bank to advertise that it is handing out taxpayer-subsidised raincoats to the banks in the face of the "black cloud" hanging over the eurozone, the UK and the global economy. But the cloud itself remains firmly in place – and will not be banished even if Greece is still inside the euro this time next week.

Still, it should be said that the "funding of lending" scheme is novel. It's a rare example of the Bank stipulating that loans must be used for a specific purpose: lending to the non-financial sector. But that, by implication, is a humiliating admission that Project Merlin, the government's last attempt to get money to small businesses, was a flop. Will the latest attempt at targeting be more successful? Until we see the details, be suspicious that the first beneficiaries will be already creditworthy individuals buying and selling houses in the south-east.